While there have been some remarkable successes and advances in the vaccination field since Edward Jenner's observation that cowpox exposure protected against smallpox, there remain great challenges to achieving protective immunity against many infectious agents and pathological conditions.
In general, a vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing entity. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and “remember” it, so that the immune system can more easily recognize and destroy any such pathogen that it later encounters.
Vaccines can be prophylactic (e.g. to prevent or ameliorate the effects of a future infection by any natural or “wild” pathogen), or therapeutic (e.g. vaccines against cancer are also being investigated; see cancer vaccine).
For immunization against cancer and pathogenic infections, conventional vaccine design focuses on, primarily, the induction of “pro-inflammatory” responses.
On the other hand, for therapy of autoimmune diseases, the prevailing concept for autoantigen vaccination is tolerance induction. However, the present use of dendritic cell-based vaccines for treatment of type 1 diabetes suffers from several limitations. For instance, dendritic cell-based vaccine requires ex vivo modification of patients' cells and introducing the modified cells into patients. Unfortunately, this approach not only adversely affects patient safety, but is also associated with high cost. In addition, the present dendritic cell-based vaccine compositions have suboptimal ex vivo stability.
Thus, there is a need for developing improved vaccine techniques and compositions for the prevention and/or treatment of infection, cancer, and autoimmune diseases. Also, there is a need for improved materials and methods for programming and modifying immune cells directly in patients' body. As will be clear from the disclosure that follows, these and other benefits are provided by the present invention.